New York Police Commissioner Ray Kelly: When asked if he’ll run for mayor, he draws a line across his neck and asks for a new line of questioning

"The last time the city felt this safe," quips the witty New York journalist James Freeman, "the Dutch were raising cattle at the bottom of Manhattan." It's true; New York City has indeed seen a total transformation in the past quarter-century-you are seven times less likely to be murdered here today than you were in 1990-and much of it can be put down directly to the leadership of its popular 71-year-old Police Commissioner, Ray Kelly. The New York Police Department (NYPD) has a 70 per cent approval rating in the polls, which Kelly considers "not bad considering how many summonses we hand out to people every year". So why on earth is he under attack?

First, the statistics: in 1990 there were 2,445 homicides in a city of 7.3 million people, but by 2012 these were down to 419 in a city of 8.4 million. Last year's murder rate was the lowest since citywide statistics were first compiled half a century ago. New York's prison population has dropped nearly 40 per cent over the past decade, whereas in the rest of the country it has risen. In 2002, when Kelly became commissioner for the second time, the NYPD numbered 35,000 policemen; now budget cuts have left him with 6,000 fewer but he still bucks every trend. Small wonder that Kelly gets standing ovations when he speaks at black churches in the Bronx and is begged to stand for Mayor when Michael Bloomberg's term expires. Yet from one section of the community, he's under near-constant assault.

The key to Kelly's success has been "broken windows" policing: cracking down hard on the small misdemeanours — trespassing, vagrancy, vandalism — before their perpetrators turn to felonies. He's also tough on the felonies. Study after study has shown how sending more people to jail for shorter periods has interrupted larger crime sprees. New York is today the safest large city in the United States, with a huge increase in the city's intake of tourist dollars the most obvious benefit. (Kelly won't make comparisons with violent, crime-ridden Chicago, but New Yorkers do all the time.)

Kelly certainly looks like a NYPD cop. He has a broken nose, a direct speaking style, and has served in every rank on the force since being a patrolman outside Macy's department store 43 years ago. He's proud of the way that his emphasis on community policing — getting his men out of the patrol cars and onto the beat — has particularly helped in the perpetual struggle between the NYPD and the street gangs. Called names like "J-Rip" and "Crewcut", these are no longer huge gangs like LA's famous "Bloods" and "Crips", but instead constitute around 220 mini-gangs who regularly fight over territory and respect. "But they then boast about it on Facebook and Twitter," reports Kelly, "using their neighbourhood slang which our juvenile division officers then decode." Some gang members actually photograph themselves in front of the intended victims' houses, and are then surprised when they get arrested shortly afterwards.